Tiger Woods preserved his seven shot lead at the WGC-Bridgestone Invitational as the World Number One moved closer to an eighth victory at Firestone Country Club.

The 14-time Major winner started the day seven shots clear of defending champion Keegan Bradley and England’s Chris Wood.

Having threatened the first 59 in European Tour history for long periods on Friday, Woods resumed in similar form with birdies at the first two holes.

A first bogey in 29 holes came at the ninth when Woods failed to get up and down, but birdies at the tenth and 13th – the latter a chip-in from off the green- soon repaired the damage.

A bogey at the 14th was followed by another dropped shot two holes later when Woods drove into a bunker and took four shots to find the green, but an eight foot birdie at the penultimate hole secured a two under par 68 and 15 under total.

That was seven clear of Sweden’s Henrik Stenson, who came home in a three under par 32 to climb back into second place.

Despite not being in the same scintillating form as Friday, Woods was delighted to grind out a score that kept his lead.

“Today was a day that I didn't quite have it, but I scored,” he said. “The name of the game is posting a number, and I did today; grinded my way around that golf course. It was playing a little blustery.

“As smooth as yesterday was, as difficult as today was, it's just one of those things where I was just trying to build on my lead somehow, and for most of the day I was doing that. It ended up being a dead push for the day, but that's not too bad either.

“I was just trying to post something in the red. It was blowing today and I thought that anything in the red today was going to be a good number, and I started off with a great start.

“I birdied the first two right out of the gate, and I figured if I could somehow just keep the card clean and not make any bogeys and maybe throw a couple more in there, it would be a pretty good day. All in all, two under par is not too bad.”

Asked whether he would be more defensive on Sunday given his sizeable advantage, Woods responded: “I’ll just go out there and execute my game plan. Whatever game plan I'm going to implement tomorrow, just go execute it.

“It all starts with what the weather is doing, and then I build it from there, and we'll see what I do tomorrow.”

American Jason Dufner sits third on seven under after an eventful round of 67 that contained seven birdies, two bogeys and a double bogey, with Wood and compatriot Luke Donald tied for fourth with Bill Haas after rounds of 70 and 68 respectively.